This year a book “GPS, GLONASS, Galileo, and BeiDou for Mobile Devices: From Instant to Precise Positioning” by author Dr Ivan G. Petrovski was published. It contains link of my article. More details about book are available through the link

This summer almost unnoticed event has happened. In june GLONASS-M (¹755) satellite with L3-band equipment was launched. Since beginning of august this satellite was included in GLONASS constellation. This means that at this moment there are two satellites capable of transmitting CDMA signals in L3 band...

On 27th of december 2012 China published full version of interface control document (ICD) for their GNSS system BeiDou-2 (COMPASS). This step opened way to building receivers that are capable of working with this GNSS.

For the moment the program works not stable. Sometimes incorrect synchronization for some channels happens and hence pseudoranges are calculated incorrectly. As a result wrong coordinates are calculated.

Some time ago I became interested in improving the precision of GLONASS Scilab receiver. The difference between mean value and max/min values of coordinates up to ±35 m for stationary receiver – is too big.

Figure 1 PVT solution of GLONASS L1 Scilab receiver

After improving several weak parts of the code the difference between mean value and max/min values of coordinates lowered to ±6 m, i.e. almost in 6 times. Results from the updated version of the receiver is on the figure 1. The same signal record as in the post GLONASS - frist experiments was used.

After a pause in developing GLONASS L2 software receiver for SciLab I found some time to work with it. The error that didn't allow to calculate correct PVT is fixed now. So GLONASS L2 scilab receiver is fully working now. PVT solution for L2 signals recorded in the may 2011 is shown on the figure 1.